nilfs2: unbreak compat ioctl
[zen-stable.git] / drivers / rtc / rtc-ds1511.c
blob586c244a05d854ab593b8310bd9e8a66991def14
1 /*
2 * An rtc driver for the Dallas DS1511
4 * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
5 * Copyright (C) 2007 Andrew Sharp <andy.sharp@lsi.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * Real time clock driver for the Dallas 1511 chip, which also
12 * contains a watchdog timer. There is a tiny amount of code that
13 * platform code could use to mess with the watchdog device a little
14 * bit, but not a full watchdog driver.
17 #include <linux/bcd.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/gfp.h>
21 #include <linux/delay.h>
22 #include <linux/interrupt.h>
23 #include <linux/rtc.h>
24 #include <linux/platform_device.h>
25 #include <linux/io.h>
26 #include <linux/module.h>
28 #define DRV_VERSION "0.6"
30 enum ds1511reg {
31 DS1511_SEC = 0x0,
32 DS1511_MIN = 0x1,
33 DS1511_HOUR = 0x2,
34 DS1511_DOW = 0x3,
35 DS1511_DOM = 0x4,
36 DS1511_MONTH = 0x5,
37 DS1511_YEAR = 0x6,
38 DS1511_CENTURY = 0x7,
39 DS1511_AM1_SEC = 0x8,
40 DS1511_AM2_MIN = 0x9,
41 DS1511_AM3_HOUR = 0xa,
42 DS1511_AM4_DATE = 0xb,
43 DS1511_WD_MSEC = 0xc,
44 DS1511_WD_SEC = 0xd,
45 DS1511_CONTROL_A = 0xe,
46 DS1511_CONTROL_B = 0xf,
47 DS1511_RAMADDR_LSB = 0x10,
48 DS1511_RAMDATA = 0x13
51 #define DS1511_BLF1 0x80
52 #define DS1511_BLF2 0x40
53 #define DS1511_PRS 0x20
54 #define DS1511_PAB 0x10
55 #define DS1511_TDF 0x08
56 #define DS1511_KSF 0x04
57 #define DS1511_WDF 0x02
58 #define DS1511_IRQF 0x01
59 #define DS1511_TE 0x80
60 #define DS1511_CS 0x40
61 #define DS1511_BME 0x20
62 #define DS1511_TPE 0x10
63 #define DS1511_TIE 0x08
64 #define DS1511_KIE 0x04
65 #define DS1511_WDE 0x02
66 #define DS1511_WDS 0x01
67 #define DS1511_RAM_MAX 0xff
69 #define RTC_CMD DS1511_CONTROL_B
70 #define RTC_CMD1 DS1511_CONTROL_A
72 #define RTC_ALARM_SEC DS1511_AM1_SEC
73 #define RTC_ALARM_MIN DS1511_AM2_MIN
74 #define RTC_ALARM_HOUR DS1511_AM3_HOUR
75 #define RTC_ALARM_DATE DS1511_AM4_DATE
77 #define RTC_SEC DS1511_SEC
78 #define RTC_MIN DS1511_MIN
79 #define RTC_HOUR DS1511_HOUR
80 #define RTC_DOW DS1511_DOW
81 #define RTC_DOM DS1511_DOM
82 #define RTC_MON DS1511_MONTH
83 #define RTC_YEAR DS1511_YEAR
84 #define RTC_CENTURY DS1511_CENTURY
86 #define RTC_TIE DS1511_TIE
87 #define RTC_TE DS1511_TE
89 struct rtc_plat_data {
90 struct rtc_device *rtc;
91 void __iomem *ioaddr; /* virtual base address */
92 int size; /* amount of memory mapped */
93 int irq;
94 unsigned int irqen;
95 int alrm_sec;
96 int alrm_min;
97 int alrm_hour;
98 int alrm_mday;
99 spinlock_t lock;
102 static DEFINE_SPINLOCK(ds1511_lock);
104 static __iomem char *ds1511_base;
105 static u32 reg_spacing = 1;
107 static noinline void
108 rtc_write(uint8_t val, uint32_t reg)
110 writeb(val, ds1511_base + (reg * reg_spacing));
113 static inline void
114 rtc_write_alarm(uint8_t val, enum ds1511reg reg)
116 rtc_write((val | 0x80), reg);
119 static noinline uint8_t
120 rtc_read(enum ds1511reg reg)
122 return readb(ds1511_base + (reg * reg_spacing));
125 static inline void
126 rtc_disable_update(void)
128 rtc_write((rtc_read(RTC_CMD) & ~RTC_TE), RTC_CMD);
131 static void
132 rtc_enable_update(void)
134 rtc_write((rtc_read(RTC_CMD) | RTC_TE), RTC_CMD);
138 * #define DS1511_WDOG_RESET_SUPPORT
140 * Uncomment this if you want to use these routines in
141 * some platform code.
143 #ifdef DS1511_WDOG_RESET_SUPPORT
145 * just enough code to set the watchdog timer so that it
146 * will reboot the system
148 void
149 ds1511_wdog_set(unsigned long deciseconds)
152 * the wdog timer can take 99.99 seconds
154 deciseconds %= 10000;
156 * set the wdog values in the wdog registers
158 rtc_write(bin2bcd(deciseconds % 100), DS1511_WD_MSEC);
159 rtc_write(bin2bcd(deciseconds / 100), DS1511_WD_SEC);
161 * set wdog enable and wdog 'steering' bit to issue a reset
163 rtc_write(DS1511_WDE | DS1511_WDS, RTC_CMD);
166 void
167 ds1511_wdog_disable(void)
170 * clear wdog enable and wdog 'steering' bits
172 rtc_write(rtc_read(RTC_CMD) & ~(DS1511_WDE | DS1511_WDS), RTC_CMD);
174 * clear the wdog counter
176 rtc_write(0, DS1511_WD_MSEC);
177 rtc_write(0, DS1511_WD_SEC);
179 #endif
182 * set the rtc chip's idea of the time.
183 * stupidly, some callers call with year unmolested;
184 * and some call with year = year - 1900. thanks.
186 static int ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
188 u8 mon, day, dow, hrs, min, sec, yrs, cen;
189 unsigned long flags;
192 * won't have to change this for a while
194 if (rtc_tm->tm_year < 1900) {
195 rtc_tm->tm_year += 1900;
198 if (rtc_tm->tm_year < 1970) {
199 return -EINVAL;
201 yrs = rtc_tm->tm_year % 100;
202 cen = rtc_tm->tm_year / 100;
203 mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */
204 day = rtc_tm->tm_mday;
205 dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
206 hrs = rtc_tm->tm_hour;
207 min = rtc_tm->tm_min;
208 sec = rtc_tm->tm_sec;
210 if ((mon > 12) || (day == 0)) {
211 return -EINVAL;
214 if (day > rtc_month_days(rtc_tm->tm_mon, rtc_tm->tm_year)) {
215 return -EINVAL;
218 if ((hrs >= 24) || (min >= 60) || (sec >= 60)) {
219 return -EINVAL;
223 * each register is a different number of valid bits
225 sec = bin2bcd(sec) & 0x7f;
226 min = bin2bcd(min) & 0x7f;
227 hrs = bin2bcd(hrs) & 0x3f;
228 day = bin2bcd(day) & 0x3f;
229 mon = bin2bcd(mon) & 0x1f;
230 yrs = bin2bcd(yrs) & 0xff;
231 cen = bin2bcd(cen) & 0xff;
233 spin_lock_irqsave(&ds1511_lock, flags);
234 rtc_disable_update();
235 rtc_write(cen, RTC_CENTURY);
236 rtc_write(yrs, RTC_YEAR);
237 rtc_write((rtc_read(RTC_MON) & 0xe0) | mon, RTC_MON);
238 rtc_write(day, RTC_DOM);
239 rtc_write(hrs, RTC_HOUR);
240 rtc_write(min, RTC_MIN);
241 rtc_write(sec, RTC_SEC);
242 rtc_write(dow, RTC_DOW);
243 rtc_enable_update();
244 spin_unlock_irqrestore(&ds1511_lock, flags);
246 return 0;
249 static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
251 unsigned int century;
252 unsigned long flags;
254 spin_lock_irqsave(&ds1511_lock, flags);
255 rtc_disable_update();
257 rtc_tm->tm_sec = rtc_read(RTC_SEC) & 0x7f;
258 rtc_tm->tm_min = rtc_read(RTC_MIN) & 0x7f;
259 rtc_tm->tm_hour = rtc_read(RTC_HOUR) & 0x3f;
260 rtc_tm->tm_mday = rtc_read(RTC_DOM) & 0x3f;
261 rtc_tm->tm_wday = rtc_read(RTC_DOW) & 0x7;
262 rtc_tm->tm_mon = rtc_read(RTC_MON) & 0x1f;
263 rtc_tm->tm_year = rtc_read(RTC_YEAR) & 0x7f;
264 century = rtc_read(RTC_CENTURY);
266 rtc_enable_update();
267 spin_unlock_irqrestore(&ds1511_lock, flags);
269 rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
270 rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
271 rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
272 rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
273 rtc_tm->tm_wday = bcd2bin(rtc_tm->tm_wday);
274 rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
275 rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
276 century = bcd2bin(century) * 100;
279 * Account for differences between how the RTC uses the values
280 * and how they are defined in a struct rtc_time;
282 century += rtc_tm->tm_year;
283 rtc_tm->tm_year = century - 1900;
285 rtc_tm->tm_mon--;
287 if (rtc_valid_tm(rtc_tm) < 0) {
288 dev_err(dev, "retrieved date/time is not valid.\n");
289 rtc_time_to_tm(0, rtc_tm);
291 return 0;
295 * write the alarm register settings
297 * we only have the use to interrupt every second, otherwise
298 * known as the update interrupt, or the interrupt if the whole
299 * date/hours/mins/secs matches. the ds1511 has many more
300 * permutations, but the kernel doesn't.
302 static void
303 ds1511_rtc_update_alarm(struct rtc_plat_data *pdata)
305 unsigned long flags;
307 spin_lock_irqsave(&pdata->lock, flags);
308 rtc_write(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
309 0x80 : bin2bcd(pdata->alrm_mday) & 0x3f,
310 RTC_ALARM_DATE);
311 rtc_write(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
312 0x80 : bin2bcd(pdata->alrm_hour) & 0x3f,
313 RTC_ALARM_HOUR);
314 rtc_write(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
315 0x80 : bin2bcd(pdata->alrm_min) & 0x7f,
316 RTC_ALARM_MIN);
317 rtc_write(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
318 0x80 : bin2bcd(pdata->alrm_sec) & 0x7f,
319 RTC_ALARM_SEC);
320 rtc_write(rtc_read(RTC_CMD) | (pdata->irqen ? RTC_TIE : 0), RTC_CMD);
321 rtc_read(RTC_CMD1); /* clear interrupts */
322 spin_unlock_irqrestore(&pdata->lock, flags);
325 static int
326 ds1511_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
328 struct platform_device *pdev = to_platform_device(dev);
329 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
331 if (pdata->irq <= 0)
332 return -EINVAL;
334 pdata->alrm_mday = alrm->time.tm_mday;
335 pdata->alrm_hour = alrm->time.tm_hour;
336 pdata->alrm_min = alrm->time.tm_min;
337 pdata->alrm_sec = alrm->time.tm_sec;
338 if (alrm->enabled) {
339 pdata->irqen |= RTC_AF;
341 ds1511_rtc_update_alarm(pdata);
342 return 0;
345 static int
346 ds1511_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
348 struct platform_device *pdev = to_platform_device(dev);
349 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
351 if (pdata->irq <= 0)
352 return -EINVAL;
354 alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
355 alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
356 alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
357 alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
358 alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
359 return 0;
362 static irqreturn_t
363 ds1511_interrupt(int irq, void *dev_id)
365 struct platform_device *pdev = dev_id;
366 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
367 unsigned long events = 0;
369 spin_lock(&pdata->lock);
371 * read and clear interrupt
373 if (rtc_read(RTC_CMD1) & DS1511_IRQF) {
374 events = RTC_IRQF;
375 if (rtc_read(RTC_ALARM_SEC) & 0x80)
376 events |= RTC_UF;
377 else
378 events |= RTC_AF;
379 if (likely(pdata->rtc))
380 rtc_update_irq(pdata->rtc, 1, events);
382 spin_unlock(&pdata->lock);
383 return events ? IRQ_HANDLED : IRQ_NONE;
386 static int ds1511_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
388 struct platform_device *pdev = to_platform_device(dev);
389 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
391 if (pdata->irq <= 0)
392 return -EINVAL;
393 if (enabled)
394 pdata->irqen |= RTC_AF;
395 else
396 pdata->irqen &= ~RTC_AF;
397 ds1511_rtc_update_alarm(pdata);
398 return 0;
401 static const struct rtc_class_ops ds1511_rtc_ops = {
402 .read_time = ds1511_rtc_read_time,
403 .set_time = ds1511_rtc_set_time,
404 .read_alarm = ds1511_rtc_read_alarm,
405 .set_alarm = ds1511_rtc_set_alarm,
406 .alarm_irq_enable = ds1511_rtc_alarm_irq_enable,
409 static ssize_t
410 ds1511_nvram_read(struct file *filp, struct kobject *kobj,
411 struct bin_attribute *ba,
412 char *buf, loff_t pos, size_t size)
414 ssize_t count;
417 * if count is more than one, turn on "burst" mode
418 * turn it off when you're done
420 if (size > 1) {
421 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD);
423 if (pos > DS1511_RAM_MAX) {
424 pos = DS1511_RAM_MAX;
426 if (size + pos > DS1511_RAM_MAX + 1) {
427 size = DS1511_RAM_MAX - pos + 1;
429 rtc_write(pos, DS1511_RAMADDR_LSB);
430 for (count = 0; size > 0; count++, size--) {
431 *buf++ = rtc_read(DS1511_RAMDATA);
433 if (count > 1) {
434 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
436 return count;
439 static ssize_t
440 ds1511_nvram_write(struct file *filp, struct kobject *kobj,
441 struct bin_attribute *bin_attr,
442 char *buf, loff_t pos, size_t size)
444 ssize_t count;
447 * if count is more than one, turn on "burst" mode
448 * turn it off when you're done
450 if (size > 1) {
451 rtc_write((rtc_read(RTC_CMD) | DS1511_BME), RTC_CMD);
453 if (pos > DS1511_RAM_MAX) {
454 pos = DS1511_RAM_MAX;
456 if (size + pos > DS1511_RAM_MAX + 1) {
457 size = DS1511_RAM_MAX - pos + 1;
459 rtc_write(pos, DS1511_RAMADDR_LSB);
460 for (count = 0; size > 0; count++, size--) {
461 rtc_write(*buf++, DS1511_RAMDATA);
463 if (count > 1) {
464 rtc_write((rtc_read(RTC_CMD) & ~DS1511_BME), RTC_CMD);
466 return count;
469 static struct bin_attribute ds1511_nvram_attr = {
470 .attr = {
471 .name = "nvram",
472 .mode = S_IRUGO | S_IWUSR,
474 .size = DS1511_RAM_MAX,
475 .read = ds1511_nvram_read,
476 .write = ds1511_nvram_write,
479 static int __devinit
480 ds1511_rtc_probe(struct platform_device *pdev)
482 struct rtc_device *rtc;
483 struct resource *res;
484 struct rtc_plat_data *pdata;
485 int ret = 0;
487 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
488 if (!res) {
489 return -ENODEV;
491 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
492 if (!pdata)
493 return -ENOMEM;
494 pdata->size = resource_size(res);
495 if (!devm_request_mem_region(&pdev->dev, res->start, pdata->size,
496 pdev->name))
497 return -EBUSY;
498 ds1511_base = devm_ioremap(&pdev->dev, res->start, pdata->size);
499 if (!ds1511_base)
500 return -ENOMEM;
501 pdata->ioaddr = ds1511_base;
502 pdata->irq = platform_get_irq(pdev, 0);
505 * turn on the clock and the crystal, etc.
507 rtc_write(0, RTC_CMD);
508 rtc_write(0, RTC_CMD1);
510 * clear the wdog counter
512 rtc_write(0, DS1511_WD_MSEC);
513 rtc_write(0, DS1511_WD_SEC);
515 * start the clock
517 rtc_enable_update();
520 * check for a dying bat-tree
522 if (rtc_read(RTC_CMD1) & DS1511_BLF1) {
523 dev_warn(&pdev->dev, "voltage-low detected.\n");
526 spin_lock_init(&pdata->lock);
527 platform_set_drvdata(pdev, pdata);
529 * if the platform has an interrupt in mind for this device,
530 * then by all means, set it
532 if (pdata->irq > 0) {
533 rtc_read(RTC_CMD1);
534 if (devm_request_irq(&pdev->dev, pdata->irq, ds1511_interrupt,
535 IRQF_DISABLED | IRQF_SHARED, pdev->name, pdev) < 0) {
537 dev_warn(&pdev->dev, "interrupt not available.\n");
538 pdata->irq = 0;
542 rtc = rtc_device_register(pdev->name, &pdev->dev, &ds1511_rtc_ops,
543 THIS_MODULE);
544 if (IS_ERR(rtc))
545 return PTR_ERR(rtc);
546 pdata->rtc = rtc;
548 ret = sysfs_create_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
549 if (ret)
550 rtc_device_unregister(pdata->rtc);
551 return ret;
554 static int __devexit
555 ds1511_rtc_remove(struct platform_device *pdev)
557 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
559 sysfs_remove_bin_file(&pdev->dev.kobj, &ds1511_nvram_attr);
560 rtc_device_unregister(pdata->rtc);
561 if (pdata->irq > 0) {
563 * disable the alarm interrupt
565 rtc_write(rtc_read(RTC_CMD) & ~RTC_TIE, RTC_CMD);
566 rtc_read(RTC_CMD1);
568 return 0;
571 /* work with hotplug and coldplug */
572 MODULE_ALIAS("platform:ds1511");
574 static struct platform_driver ds1511_rtc_driver = {
575 .probe = ds1511_rtc_probe,
576 .remove = __devexit_p(ds1511_rtc_remove),
577 .driver = {
578 .name = "ds1511",
579 .owner = THIS_MODULE,
583 static int __init
584 ds1511_rtc_init(void)
586 return platform_driver_register(&ds1511_rtc_driver);
589 static void __exit
590 ds1511_rtc_exit(void)
592 platform_driver_unregister(&ds1511_rtc_driver);
595 module_init(ds1511_rtc_init);
596 module_exit(ds1511_rtc_exit);
598 MODULE_AUTHOR("Andrew Sharp <andy.sharp@lsi.com>");
599 MODULE_DESCRIPTION("Dallas DS1511 RTC driver");
600 MODULE_LICENSE("GPL");
601 MODULE_VERSION(DRV_VERSION);